1. Field of the Invention
This invention relates to a method and apparatus for construction of self-supporting buildings of the type comprising arcuate interlocking panels and in particular to interlocking panels having a joint of the type described in my co-pending application Ser. No. 083,909 now U.S. Pat. No. 4,759,159.
2. Description of the Prior Art
The prior art discloses numerous examples of interlocking building panels which secure together without any additional locking means such as crimping, bolting, or the like. Typical examples of such panels are described in U.S. Pat. Nos. 4,109,437 (PLAYER et al); 4,223,503 (HAGUE); 4,192,117 (HEIRICH); 4,463,533 (MULLET); 3,606,718 (CURRAN), German Patent No. 2,205,479 (KASPAR) and Russian Patent No. 1,054,5112.
Each of the above patents is concerned with interlocking planar panels which in use must be supported by a support member extending transversely to the interlocking joints between adjacent panels. In building construction the support member is typically a building framework to which the interlocking panels are affixed by bolts etc. to form roof and wall surfaces.
It is known to form a self-supporting structure from arcuate interlocking panels. Typical examples of such arcuate structures are described in U.S. Pat. No. 3,276,171 (BROWN); Swiss Patent No. 332,721 (CENTRAL FARM EQUIPMENT COMPANY, CHICAGO, ILL.), and U.S. Pat. No. 3,902,288 (KNUDSON).
Brown describes an arcuate continuous channel shaped panel which interlocks with adjoining panels in edge to edge relationship by engaging opposed ends of adjacent male and female interlocking ribs and then longitudinally sliding the interengaging edges together. Although when assembled a strong weatherproof joint is achieved, considerable force is required to effect the sliding joint due to increasing frictional engagement and this may require substantial reinforcing (at least temporary) of the building structure to withstand these forces. This method of building construction is limited to elevated arcuate self supporting roofs of relatively large arcuate diameter due to the arcuate extension of a panel being joined to an adjacent panel in situ on the roof.
Swiss Patent No. 332721 (CENTRAL FARM EQUIPMENT COMPANY) describes the use of short arcuate panels which are joined at opposing ends and opposing edges by bolted connections passing through perforations in the panels to form an arcuate roof structure. The erection of such structures is highly labour intensive and suffers the disadvantage of leak prone jointing means passing through perforations in the panels.
KNUDSON describes an arcuate panel having a trough shaped cross section. The panels of this invention are joined above abutting edges by a simple crimped joint which is formed by folding a flange along a free edge of one panel through 90.degree. to engage a flange of an adjoining panel. When steel sheet employing a corrosion resistant coating of zinc, zinc alloy or polymeric materials is utilized, stress cracking of the corrosion resistant coating can occur with subsequent corrosion of the crimped joint.
The KNUDSON specification also discloses a method and apparatus for roll forming of arcuate panels having a trough-like cross sectional shape. The general description of the roll forming apparatus and method is incorporated in the present description by way of cross-reference.